This invention relates to a biphenyl derivative, a composition for nerve cell degeneration repairing or protecting agent, and process for preparing a phenyl derivative contained in the composition.
Recently it is indicated that in the senile dementia such as Alzheimer disease, the central cholinergic nervous system has a serious change and that the function deteriorates (Perry, E. K. and Perry, R. H.: "Biochemistry of Dimentia", John Wiley & Sons, p. 135, 1980).
Therefore, a compound having repairability (survival effect and expanding effect of nerve process) and protective action can be efficiently used as a therapeutic or preventive agent for defects of intelligent learning such as senile dementia by Alzheimer disease, Down syndrome, Huntington chorea, amnesia and defects of memory, and sequelae and mental disorders based on the deteriorated function of the central cholinergic nervous system caused by cranio-cerebral injuries, cerebral operation, drug intoxication, circulatory disorders, cerebral metabolic disorders and encephalitis (J. W. Geddes, et al.: Science, 230, 1179-1181, 1985).
Conventionally, as compounds having the nerve cell degeneration repairability as mentioned above, only NGF (nerve growth factor), GM.sub.1 (ganglioside) or the like have been known. The NGF is described in the Neuroscience (Hefti, F., et al. 14, 55-68, 1985), the Journal of Neuroscience (Franz Hefti, 6, 2155-2162, 1986), the proceedings of the Natural Academy of Science of the U.S.A. (L. R. Williams, et al., Proc. Natl. Acad. Sci. U.S.A., 83, 9231-9235, 1986) and the Science (L. E. Kromer, 235, 214-216, 1986). The GM.sub.1 is described in the Science (Fred J. Roisen, et al., 214, 577-578, 1981), the Brain Res. (M. V. Sofroniew, et al., 398, 393-396, 1986), the Brain Res. (M. Gradkowska, et al., 375, 417-422, 1986).